Stoker air control



O. O. NYGAARD sToKER AIR CONTROL Dec. 18, 1928. 1,696,144

Filed July 51, .1925 2 Sheets-Sheet 1 Patented Dec. 18, 1928.

UNITED "STATES PATENT OFFICE.

OSCAR O. NYGAARD, OF SAUGUS, MASSACHUSETTS, ASSIGNOR TO COMBUSTION EN- GINEERING CORPORATION, OF NEVIYORK, N. Y., A CORPORATION 01 NEW YORK.

STOKER m CONTROL.

Application filed July 31, 1925. Serial No.,47,265.

My present invention relates to stokers, and more particularly to an improved apparatus for distributing and regulating the flow of air to the fuel bed in automatic stokers.

In stoking apparatus, and particularly automatic stoking apparatus the types in use at the presentday, and with the type of fuel necessarily employed therewith it becomes essential for a proper economical working of the apparatus to provide oxygen containing fluid, such as air,'to the fuel bed in pro ortion to the depth of the fuel in the be at any point throughout the length thereof, and, in the past, although many attempts have been made to devise means for regulating the amount of air in the fuel bed, all such devices have failed to function properly as they operated over too great an area of\ the stoker. The tendency in automatic stokers is for the units to become larger and larger as time goes on with the result that the difference in the thickness of the fuel bed'on the grate at the receiving or inletend and at the dumping or. exit end is continually increasing.

I In my copending application, Serial No. 627,065, .filed March 23, 1923, I have described and claimed an improved apparatus for regulating the flow of air to the fuel bed in automatic stokers and the present application is to be considered as a continuation I in part of such application, the form of cation, this form utilizing but a single form of tuyere forming block, the means for regulating the amount of air passing through the tuyeres being located on a separate means carried by the sides of the fuel trough and acting as a support for the tuyere blocks.

The object of my invention, therefore, is an improved apparatus for regulating the flow of air through a plurality of superimposed tuyereforming blocks and into a fuel bed.

In the accompanying drawings illustrating the preferred embodiment of my invention,

Fig. 1 is a sectional side elevation through a row of tuyres showing my invention associated therewith; Fi 2 is a vertical sectional elevation on the line 2-2 of Fig. 1;

Fig. 3 is a front elevation of the frame members shown in Fig. 1;

Fig. 4 is a vertical sectional side elevation of the tuyere forming block employed in. this modification of my invention;

Fig. 5 is a fragmentary plan view of the tuyere forming block shown in Fig. 4, and

Fig. 6 is a sectional elevation on the line 66 of Fig. 1.

Referring to the drawings, 10 designates the foundation on which is mounted the spaced fuel troughs 11 constituting supports for the tuyere blocks, and 12 designates a portion of the brick masonry enclosing the stoker apparatus, a channel iron 13 extending across the furnace and acting as a support for the front ends of the fuel troughs 11,-,a plate 14 closing the space extending between the side walls 15 and the base 10 and channel iron 13.

Secured to the sides of the troughs 11 by bolts 16 is a frame 17 provided on the inner opposite faces with spaced projections 18 and spacing bars 19, the opposite projections 18 being in alignment, as clearly shown in Figs. 2 and 3. It will be noted from an inspection of Fig. 3 that the'various pairs of projections 18 differ in length,

thus providing passages through the spaced frames 17 of different cross sectional area. In my invention I utilize a tuyere forming block of the form illustrated particularly in Figs. 4 and 5 and designated generally by the numeral 20, this block consisting essentially of a floor plate 21 provided on the face and on the forward side edges with laterally projecting flanges 22, each flange being provided with a plurality of grooves 23 which, when the tuyere block is in assembled position in the apparatus, form, with the grooves of the adjacent tuyere blocks, orifices through'wvhich air from a wind or air chamber may flow. The space defined by the under surfaces of the troughs 11 and the rearward surface of the channel 13, plate 14, and the upper surface of the base 10 forms an air or wind box 24 which receives air through a flue 25 provided with an adjustable damper 26 and by means of which the air may be regulated. In assembling the form of tuyere block employed,

the floor plate 21 is pushed into and through the space between the projections 18 and the adjacent spacing bar 19 on the frame 17, the front ends of the floor plates being each provided with perforations 27 through which is passed a stud or bolt 28 which locks thetuyere block in position and whereby each tuyere block ma be inde pendently removed and replacecli \Vhile the cross sectional area of the space between tuyerc blocks as defined by the projections 18 is suflicient to properly proportion the amount of air passing through the tuyeres and to any portion of the fuel bed 29 on said tuyeres, and therefore no other means of regulating the How of air from the wind box 2-1 is necessary, yet it may sometimes happen that it is desirable to completely shut off the flow of air through the tuyere blocks or through any one bank of the same. In order to provide for this con-- tingency I have utilized the form of damper or shutter disclosed in the application of which this is a continuation in part, and have associated with each bank of tuyeres a structure consisting of a plurality of generally downwardly extending levers 30 each pivotally secured to the side or wall of the trough 11 by bolt 31, and each of the levers 30 is provided with a longitudinally extendingislot 32. Pivotally secured to the levers 30 by pins 33 is a rod or bar 34 and by means of which the levers 30 may be operated simultaneously. Pivotally mounted in suitable bearings in the troughs 11 and extending transversely of the stoker is a shaft 35. Rotatably mounted on said shaft at intervals and extending upwardly therefrom are arms 36, each provided with a longitudinally extending slot 37 which fits over a pin 38 secured to, and extending laterally from, the rod or bar 34. Each member 36 may be so arranged as to be operated independently and thus each member 36 may control simultaneously all of the levers 30 of a'bank of levers. In place of the above, I may provide a means for operating all of the members 36 simultaneously and in this event each member 36 is rigidly attached to the shaft 35, while also attached to the shaft 35 and extending downwardly therefrom is a member 39 which has pivotally secured at its lower end a forwardly extending operating rod 40 and by means of which the shaft 35 may be rocked. Secured to each of the levers 30 adjacent to the pivot bolt '31 is a damper plate 41, each plate covering the space occupied by a plurality of tuyere blocks 20. It is possible, therefore, to shut off the flow of air from a wind box 24 to any one of the fuel troughs 11 or to the entire bank of troughs 11 1n a stoker.

While I have necessarily shown and described the preferred embodiment of my invention somewhat in detail, it is to be understood that I may vary the size, shape, and arrangement of parts within wide limits without departing from the spirit of the an airchannel at each side thereof, frames 011 said fuel trough, tuyeres arranged in stacked relation mounted on said frames, capping said channels, dampers for closing said air channels at will, each tuyere having a floor plate, and means located between 30 adjacent floor plates for determining the amount of air passing through each tuyere.

2. In an automatic stoker, a fuel trough, means to feed fuel into and out from said trough, an air channel'at each side thereof, 35

dampers for closing said air channels at will, a frame on said trough, tuyeres capping said air channels and connected to said frame, and means in the frame for determining the flow of air through each tuyere.

3. In an automatic stoker, a fuel trough, means to feed fuel into and out from said trough, an air channel at each side thereof, a frame on said trough, tuyeres capping said air channels and connected to said frame,

and means in the frame for determining the flow of air through each tuyere.

4. In an automatic stoker, a pair of fuel troughs arran ed parallel to and spaced apart from eac other and defining by such spaced relation an air channel, frames secured to the opposing faces of the fuel troughs,'tuyeres arranged in stacked relation mounted on said frames and capping said channels, dampers for opening or closing said air channels at will, each tuyere having a floor plate and means located between adjacent floor plates for determinin the amount of air passing through each tuyere.

5. In an automatic stoker, a fuel trough, an air channel at each side thereof, frames mounted on the margins of said trough, tuyre forming blocks arranged in stacked relation mounted on said frames and cap-;

ing said chambers, each of said blocks havmg a floor plate, dampers for closing said channels at will, and means located between adjacent floor plates for controlling the amount of air passing through the respective tuyeres.

In testimony whereof, I have signed my name to this specification.

OSCAR O. NYGAARD. 

